Originally posted by WR Moore:
By NYPD stats-corrected for errors-the average expenditure is 4.7 rounds per bad guy. That doesn't leave you much margin with 10 rounds. Remember: No plan survives contact with the enemy.
4.7 rounds per bad guy? If our hypothetical good guy NEEDS five rounds to put one hypothetical bad guy down, either the BG is doped on PCP or wearing armor, in which case the GG is pretty much hosed no matter what he/she is carrying, or the GG missed with the first three, in which case he/she needs not to be licensed. If the GG is simply dumping five rounds into the BG for insurance purposes, that also raises major questions about his/her fitness to hold a license, because it should have been clear after the first two that the BG was or was not going to continue causing trouble; the additional three just open the door to unnecessary-force charges, to say nothing of the complete and utter ruin the GG would face if, God forbid, he/she hit a bystander through a miss or a bullet overpenetration.
Then again, if those figures are meant to be representative of NYPD officer-involved shootings and not CPL-holder-involved shootings, the quoted number makes a little more sense. God bless 'em, but there do seem to be a lot of law enforcement agencies that subscribe a little too enthusiastically to the "curtain of lead" theory of pistol marksmanship. DPD, for a notable local example.

Other reasons to consider a reload and a second gun. Breakage-ever break a firing pin or extractor? I've had an extractor break during a match. Sobering experience. Also, if your normal shooting hand gets dinged. Yeah, the gun may stay operable, gonna bet your life on it?
I understand where you're coming from, but that's a bit of a slippery slope to start down. At what point do you define "enough" redundant backups, and more to the point, how do you conceal all this on your person without looking like Dirty Harriet? One pistol, a magazine and a pocketknife is about the maximum I can manage, and even that is rather pushing it; realistically, it's a pistol and a mag OR a knife, not both. In my daily life, the knife tends to be more useful, so the mag gets left home. Moreover, at least in this state, the law on CPL deadly force is pretty specific: while I don't have to retreat first, I can only draw to defend myself from the direct, immediate threat of death, maiming or rape. All of those are one- or at max, two-offender crimes. If I'm beset by a dozen heavily armed men, I likely have bigger problems than whether or not my weapon is going to break.
::shrugs:: Different strokes for different folks, I guess.